Seed Productivity of Natural Vegetation at UoD Campus as Affected by Mowing Frequency

Abstract

Since 2000, there has been a noticeable increase of overgrazing in Kurdistan region of Iraq, particularly in Duhok governorate, as a result of the widespread movement of livestock (sheep and goats) by animal breeders from the middle of Iraq, particularly from the Nineveh steppes, to graze in Kurdistan region constantly from early spring to late summer. In addition to local livestock, tens of thousands of animals contributed to increased grazing frequencies, overgrazing, and degradation of rangelands in countless and extensive patches. The occasional fires, droughts, and overgrazing over the past three decades have all contributed significantly to that same degradation of rangeland in Iraq, specifically in the Kurdistan region, by depleting the soil seed bank, which is the fundamental source of natural vegetation restoration. As a result, this study was carried out in the spring of 2016 in Duhok Governorate to ascertain the impact of mowing frequencies (as consequences of grazing) on the seeds productivity of natural vegetation cover (total seeds, grasses seeds, legumes seeds, and other seeds productivity), and to determine the appropriate mowing frequencies to improve vegetation cover and make rangelands more sustainable. Four treatments —no mowing, once, twice, and three times— with five replications in (RCBD) experiment were implemented. The findings showed that the productivity of all seeds declined as mowing was repeated (once, twice, and three times), with the exception of (other seeds group), whose productivity improved when mowed twice in comparison to once. Natural vegetation cover can be utilized (mowed) or grazed even twice if the plant growth season has not yet exceeded the middle stage.